I have just started breeding them. I was lucky enough to get a 4IV from the fossil, and I have a JPN Ditto that I'm breeding with as well... but I have never bred this Pokemon before and I was hoping for some more experienced insight.
Any assistance would be most welcome. :)
The best nature should be Jolly, as Tyrunt, Tyrantrum are slow, so this will boost its speed.
Its reccomend ability is Strong Jaw, which powers up biting moves.
Hope I helped.